Has he a black time at the weekend? (6)
I believe the answer is:
knight
'has he a black' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'time at the weekend?' is the wordplay.
'time' becomes 'night' (night is a kind of time).
'at' is a charade indicator (letters next to each other) (I've seen this in other clues).
'the weekend?' becomes 'k' (I've seen this in other clues).
'night' put after 'k' is 'KNIGHT'.
Can you help me to learn more?
(Other definitions for knight that I've seen before include "Holder of non-hereditary title in UK" , "Chesspiece (in shining armour?)" , "Give title of 'Sir' to" , "cavalier" , "Mounted warrior of feudal times" .)